Field of the Invention
The invention relates to a circuit configuration having a smart card module and a coil connected thereto.
German Patent DE 30 29 667 C2 shows a circuit configuration in which a flexible, non-conductive sheet is provided on one side with a conductive layer. Recesses are, for example, stamped into the sheet, so that the side of the conductive layer which faces the sheet is accessible through the recesses. The conductive layer is subdivided, for example by etching grooves, into mutually electrically insulated contact regions, with each contact region of the conductive layer being assigned a recess in the sheet. A semiconductor chip which is connected to the contact regions through the use of bonding wires is inserted into one of the recesses, preferably in a central recess. The semiconductor chip and the bonding wires are potted with a protective casting resin. That circuit configuration, which is a so-called carrier element, is inserted into a plastic card, that is alternatively referred to as a smart card, with the contact regions lying approximately in one plane with a smart card surface. As a result of that structure, a reading station can supply power and exchange information with the semiconductor chip through the use of mechanical contacts.,
A further example of a circuit configuration with contacts is shown by Published European Patent Application 0 254 640 A1. In that example, recesses are stamped into a metal surface so that the recesses define contact regions which are linked only through a frame and are designated as a lead frame. Disposed on a central contact region is a semiconductor chip which is conductively connected to the other contact regions through the use of bonding wires. The configuration is potted with synthetic resin in such a way that only the outwardly pointing parts of the contact regions remain uncovered as contact lugs, are insulated from one another by removing the supporting frame and can serve for making contact with the semiconductor chip.
In the case of the two known circuit configurations, the power needed to supply the semiconductor chip as well as the data flow from and to the semiconductor chip are handled through the contact lugs through the use of mechanical contacts.
German Patent DE 41 15 065 C2 discloses, for example, a device for contactless data and power transmission. In that example, the semiconductor chip is connected to two coils through which data and power are conveyed in a contactless manner, for example through the use of transformer transmission.
Such smart cards containing circuit configurations with coils are manufactured in large numbers. It is therefore necessary to use a method for their manufacture which is fast, inexpensive and can be automated, though it does necessitate the use of a suitable structure of the circuit configuration.
It has emerged from analyses of previous concepts using contactless smart cards that in those cases the ends of the coil are arbitrarily routed, and crossed over the coil, to connection points at the semiconductor chip, although that is disadvantageous for automation since a coil end crosses over the coil at any point. Such a coil having an increasing thickness is unfavorable, since the cover layers of the card have to compensate for the unfavorable height levels, resulting in some cases in severe changes in shape of the PVC plastic sheets. Since the cover layers are generally provided with print which is visible to the user, that is to say they represent a design part and local deformations in the region of the coil crossing points, which have an undefined location, can lead to undefined print distortions.